
By Stan Purdum

Hot
- Stops charging dogs in their tracks
- Sound can be heard by drivers with windows closed
- Easy-to-reach trigger
- Lightweight
- Adjustable volume control
- Air canister can be placed in water bottle cage
- Sold by company with good reputation for customer support
Not
- Air canister has a Schrader valve, which will not work if your pump accommodates only Presta valves
- Installation directions could be clearer
- Installation may require some adaptations
- Post-purchase application of UV protectant to tubing recommended
Price: $44.99 (Delta)
Weight: 0.5 lbs / 227 grams
How Obtained: Company sample
Availability: Online Directly from Manufacturer as well as Retail and Amazon
RBR Advertiser: No
In an RBR newsletter earlier this year, I answered a reader’s question “How do cyclists deal with dogs?” and as one option, I mentioned using an air horn. At the time, I hadn’t tried that method myself, but I included a video showing dogs giving up the chase when a blast from an Airzound Horn from Delta was sounded. A friend who had used the horn and had a videocam on his bike provided the footage.
I have since tried the Airzound and have had similar results with charging dogs. That’s important to me because my riding area includes lots of rural roads with unrestrained canines.
My only use of the Airzound has been to halt dogs, but some purchasers say they have used it to clear geese or sheep off the path in front of them, and a few mentioned tooting at drivers who were crowding them off the road. Delta says, “More prominent than a traditional bike bell, the Airzound can penetrate a car interior, ensuring guaranteed awareness of your presence.” The horn is very loud — 115 decibels at the full volume setting, which is too much to be a friendly toot at pedestrians — and its sound reminds me of the old semi-truck air horns. There is a knob that enables you to reduce the volume. But really, given the purpose of the horn, why would you want to?
The horn operates on air you pump into the attached canister with your bicycle pump — up to 80 psi maximum. The fill valve, which is on the horn itself, right under the trigger, and connected to the bottle by means of a plastic tube, is a Schrader valve, which means it cannot be filled on the road if your frame pump accommodates only Presta valves. However, I fill the canister before leaving home, using my floor pump, which accepts either valve.
The installation instructions suggest applying a UV protectant, such as Armor All, to the tubing to extend its life. I wondered why that hadn’t been applied by Delta during the manufacture of the horn.
On my first ride with the Airzound installed, I sounded a short blast when a barking dog charged me from a house I was passing. Not only did the barking stop instantly, but when I turned my head to look, the dog was nowhere in sight; apparently he’d done an abrupt about face.
During my next ride, three different dogs launched attacks in separate encounters. In each case, when I fired a short blast, the animal stopped quickly. None of them ran away, but neither did they resume their charge. To the degree it’s possible to “read” a dog’s expression, it seemed to me that the horn blast brought a look of puzzlement to the pooch’s face.
A few days later I was pedaling a route I often use when I don’t have a lot of time, but want to get some riding in nonetheless. I wasn’t even thinking about needing the horn because I’d never seen any loose dogs on this route. But I was riding it in midafternoon, not my usual time of day on those roads, and this time, my passage was challenged by no less than five dogs in four incidents (two dogs at one of them). When I saw a teenage boy in the yard with one of the canines and recalled that I had played leapfrog with a school bus at the beginning of the ride, I realized what was happening: The dogs had been confined in the families’ houses all day, and when the kids got home from school, they let the dogs out to relieve themselves, without putting them on leashes. And then I came riding along.
Happily, in each case, blasts from my horn stopped each of the attacks. At the two-dog house, one of the animals did continue to bark and run along the edge of his unfenced yard as I rode on, but after I sounded the horn, he never left the yard. Of course, my experience is no guarantee that the horn will be effective against every mutt, but my tests so far have made me more confident in these encounters.
I think I sounded the horn five times on that ride. When I got home, I checked the air pressure in the bottle to see whether the multiple uses had emptied the air bottle, I found it still had 40 psi. So I pumped the canister back up to 80 psi, and repeatedly sounded the horn. I got 10 strong short blasts and a couple of weaker ones before the air supply was exhausted. Sounding the horn when out in the open and moving along the road did not bother my ears, but standing beside it while test blasting it was painful. After one blast, I put on my gun-range-quality ear protection to complete the test, and even with those, I could still hear the horn.
I again refilled the canister and then went a week without riding that bike. When I checked the air pressure before my next ride, I found that in that time, the psi had decreased by only five pounds, so the leakage is minimal.
Installing the horn on a bike is not difficult, but the directions could be clearer. Inside the packaging there’s a plastic bag with some small parts and a folded sheet of paper with text printed on it. It’s natural to assume this is the installation directions, but when you unfold the paper, it is troubleshooting instructions (which I haven’t needed so far). The installation directions, it turns out, are printed on the side of the box the horn came in, where the steps are presented in a logical order. If you are uncertain, however, the box says there’s an assembly video on the Delta website, and it provides the web address. When you go there, however, what you find is not a video but a PDF of the same directions that are on the box (though I found the PDF easier to read than what was on the box). Likewise, if you use the provided QR code instead of the web address, you still get only the PDF. Nonetheless, because the installation isn’t complicated, the absence of the video is not a huge hurdle.
The directions say that the air canister can be placed in a water bottle cage, but they also provide materials to mount it elsewhere on the bike if you wish. I used that option, as I didn’t want to lose the use of a bottle cage. If you do use a cage, however, be aware that the canister fits so loosely that it’s likely to bounce out while riding. You can fix this by slipping an old sock over the canister and/or using the provided Velcro strap to secure the canister.
The alternative arrangement involves cable tying a provided Velcro swatch to the frame, which then adheres to the Velcro on the canister, and then further securing the canister with the provided Velcro strap. While the whole deal looks a bit flimsy, it’s proven surprisingly secure over the many miles I’ve ridden since installing it on the bottom side of my bike’s downtube.

For mounting the horn itself, the kit comes with two sizes of plastic mounting brackets, the smaller of which will fit most handlebars. But because I didn’t have room on the bars, I mounted the larger bracket on the handlebar stem. Since this was a bit of stretch even for the larger bracket, I had to purchase a longer bolt from my local hardware store to secure it. Also, because the plastic bracket was slippy on the stem, I first wrapped the stem with some friction tape and then topped that with a bead of thick adhesive. (It’s very important that the bracket doesn’t move because sounding the horn requires pushing down on the trigger, which, if the bracket slips, causes the horn to move down under the pressure on the trigger without sounding.)

The horn snaps into place on the bracket, and some users have said it can work loose and fall down, suspended by the tube. I’ve not had that problem but those who have suggest placing a cable tie through the horn and around the handlebar.
So yes, installing the horn system may require a little tinkering, but the first time you see a charging dog stop short when you sound it will make it all worth it.
Stan Purdum has ridden several long-distance bike trips, including an across-America ride recounted in his book Roll Around Heaven All Day, and a trek on U.S. 62, from Niagara Falls, New York, to El Paso, Texas, the subject of his book Playing in Traffic. Stan, a freelance writer and editor, lives in Ohio. See more at www.StanPurdum.com.
Stan, is the hose length adjustable? I’m thinking of mounting it under the bike’s top tube and horn either on the stem or handlebar. Looks like the hose is rather long and I would have to fold the hose up in some fashion.
DL, the hose does not appear to be adjustable. It’s about 32 inches long, but a couple of the inches are used up where the hose threads though the turns of the horn. I understand that’s to keep the horn from dropping to the road should it be come detached from it’s mount.
Stan
Hi, Stan. I find the Airzorn horn’s tubing far too long on my bike (I don’t really want to wind it around the frame since that looks unsightly) and I wondered if there is a feasible (and successful) way to shorten it without compromising its effectiveness.
Thanks,
Alan.
Alan,
There’s no easy way I can see. At the horn end, the tube goes inside the horn. But it might be possible at the air cannister end. There, the tube goes into the cannister cap. The cap, however, does not appear to screw off, but rather appears to be pressed onto the cannister. I don’t know if forcing it off would damage the air-holding integrity of the cannister.